LOK: Impress reads every slide as a show plays it

.uno:SlideShow lists each slide: hidden, notes as text, the transition
and effects in the .uno:SlideTransition and .uno:SlideAnimations shapes,
and its media with frames. .uno:SlideMedia entries carry their frame,
x, y, width and height in 1/100 mm.

diff --git a/sd/source/ui/unoidl/unomodel.cxx b/sd/source/ui/unoidl/unomodel.cxx
index d8f1dee..035566a 100644
--- a/sd/source/ui/unoidl/unomodel.cxx
+++ b/sd/source/ui/unoidl/unomodel.cxx
@@ -2067,7 +2067,8 @@ bool SdXImpressDocument::supportsCommand(std::u16string_view rCommand)
 {
     return rCommand == u"SlideDesign" || rCommand == u"SlideObjects" || rCommand == u"Chart"
            || rCommand == u"SlideNotes" || rCommand == u"SlideTransition"
-           || rCommand == u"SlideAnimations" || rCommand == u"SlideMedia";
+           || rCommand == u"SlideAnimations" || rCommand == u"SlideMedia"
+           || rCommand == u"SlideShow";
 }
 
 namespace
@@ -2226,12 +2227,12 @@ void lcl_SlideNotes(::tools::JsonWriter& rJson, SdDrawDocument& rDoc, sd::DrawVi
     rJson.put("rich", pText && !sd::DrawViewShell::NotesLook(pText->GetTextObject(), rDoc.GetPool()));
 }
 
-/// The shown slide's media: list place, file, link.
-void lcl_SlideMedia(::tools::JsonWriter& rJson, sd::DrawViewShell& rShell)
+/// A slide's media: list place, frame, file, link.
+void lcl_SlideMedia(::tools::JsonWriter& rJson, SdPage& rPage)
 {
     sal_Int64 nAt = 0;
     auto aList = rJson.startArray("media");
-    for (const rtl::Reference<SdrObject>& pObj : *rShell.GetActualPage())
+    for (const rtl::Reference<SdrObject>& pObj : rPage)
     {
         if (pObj->isAnnotationObject())
             continue;
@@ -2249,11 +2250,38 @@ void lcl_SlideMedia(::tools::JsonWriter& rJson, sd::DrawViewShell& rShell)
             rJson.put("file", aFile);
             rJson.put("missing", aFile.isEmpty() || osl::DirectoryItem::get(aFile, aItem) != osl::FileBase::E_None);
             rJson.put("loop", rItem.isLoop());
+            const ::tools::Rectangle& rRect = pMedia->GetLogicRect();
+            rJson.put("x", sal_Int64(rRect.Left()));
+            rJson.put("y", sal_Int64(rRect.Top()));
+            rJson.put("width", sal_Int64(rRect.GetWidth()));
+            rJson.put("height", sal_Int64(rRect.GetHeight()));
         }
         ++nAt;
     }
 }
 
+/// Each slide for a show: hidden, notes, motion, media.
+void lcl_SlideShow(::tools::JsonWriter& rJson, SdDrawDocument& rDoc)
+{
+    auto aList = rJson.startArray("slides");
+    for (sal_uInt16 i = 0; i < rDoc.GetSdPageCount(PageKind::Standard); ++i)
+    {
+        SdPage* pPage = rDoc.GetSdPage(i, PageKind::Standard);
+        SdPage* pNotes = rDoc.GetSdPage(i, PageKind::Notes);
+        auto pObj = pNotes ? dynamic_cast<SdrTextObj*>(pNotes->GetPresObj(PresObjKind::Notes)) : nullptr;
+        const OutlinerParaObject* pText = pObj && !pObj->IsEmptyPresObj() ? pObj->GetOutlinerParaObject() : nullptr;
+        auto aOne = rJson.startStruct();
+        rJson.put("hidden", pPage->IsExcluded());
+        rJson.put("notes", pText ? pText->GetTextObject().GetText(LINEEND_LF) : OUString());
+        {
+            auto aTransition = rJson.startNode("transition");
+            DrawViewShell::WriteKitTransition(rJson, *pPage);
+        }
+        DrawViewShell::WriteKitAnimations(rJson, *pPage);
+        lcl_SlideMedia(rJson, *pPage);
+    }
+}
+
 /// The shown slide's objects, selection, guides and snapping.
 void lcl_SlideObjects(::tools::JsonWriter& rJson, sd::DrawViewShell& rShell)
 {
@@ -2325,7 +2353,12 @@ void SdXImpressDocument::getCommandValues(::tools::JsonWriter& rJsonWriter, std:
     if (rCommand == ".uno:SlideMedia")
     {
         if (DrawViewShell* pShell = GetViewShell())
-            lcl_SlideMedia(rJsonWriter, *pShell);
+            lcl_SlideMedia(rJsonWriter, *pShell->GetActualPage());
+        return;
+    }
+    if (rCommand == ".uno:SlideShow")
+    {
+        lcl_SlideShow(rJsonWriter, *mpDoc);
         return;
     }
     if (rCommand == ".uno:SlideTransition" || rCommand == ".uno:SlideAnimations")